An apparatus of this kind is known, for instance from German Pat. No. 30 02 636. To this end, it serves to tear open the meat tissue and open up the meat cells so that the pickling brine can enter them more easily. In particular, this pressure treatment is intended to open up the protein cells, in which the pickling brine is bound.
In German Pat. No. 30 02 636, a pair of pressure rollers is used for pressure treatment; one pressure roller is provided with studs extending along the jacket lines, while the other roller, as the transporting roller, has a smooth surface. Other forms of surfaces are also known, however, such as those having protrusions, teeth, knives, needles and the like; all of them have the task of increasing the surface area of the meat that is to be treated and opening up the cells.
These known pressure rollers function more or less satisfactorily; however, either the increase in surface area that is effected is not very great, or the meat is torn up so coarsely--that is, such deep cuts are made--that air is trapped in the meat. This trapped air, however, provides a fertile field for bacteria, and the meat becomes considerably more perishable.